Field of the Invention
This invention relates generally to vehicle systems and networks, such as railway systems including trains travelling in a track or rail network, and in particular to a switch alignment detection and enforcement system and method for use in a vehicle network, preferably a vehicle network of multiple trains operating in a track network, where the track network includes multiple operable switches to facilitate the trains moving between track sections.
Description of Related Art
Vehicle systems and networks exist throughout the world, and, at any point in time, a multitude of vehicles, such as cars, trucks, buses, trains, and the like, are travelling throughout the system and network. With specific reference to trains travelling in a track network, the locomotives of such trains are typically equipped with or operated using train control, communication, and management systems (e.g., positive train control systems), such as the I-ETMS® of Wabtec Corp. In order to effectively manage all of the trains, information and data must be communicated and distributed over the network between the trains, i.e., the locomotives; a central control system, i.e., central dispatch; various wayside devices, e.g., wayside interface units, radios, track communication devices; and/or other equipment positioned throughout the track network.
Further, and as is known, switches and switch arrangements are sections of tracks and movable rails that are used to allow the train to move between and among tracks as it travels along it route, such as moving between a normal leg and a reverse leg. The switches in such systems are monitored to support navigation, and to provide status for protection of a switch that is not properly positioned (or aligned) for a train's authority. In signaled territory, these switches are directly monitored through a wayside interface unit, or may be indirectly monitored by an electrical lock arrangement, as provided through the signal status. However, in “dark” (i.e., non-signaled) territory, switch monitors are generally not available and new infrastructure is or would be required to meet the monitoring requirements of the positive train control system.
FIG. 1 illustrates an existing switch monitoring arrangement for use in dark territory. As shown in FIG. 1, a wayside arrangement (A) is provided, which is used in connection with a switch (S) at a juncture in the track (T). This wayside arrangement (A) includes a circuit controller (CC) as a signal source for a wayside interface unit (WIU) for indicating that the switch (S) is either in the normal or reverse position. A data radio (DR) is integrated or in communication with the wayside interface unit (WIU), and this data radio (DR) conveys or transmits the status of the wayside interface unit (WIU) to an appropriately equipped locomotive, i.e., a train having a train management computer and operating in a positive train control system. Further, a power source (PS) is used to power the devices in the wayside arrangement (A), and may include commercial power (if available), locally-generated wind power, locally-generated solar power, and/or the like. Further, the data radio (DR) transmits the information to a communication device (CD) on a train (TR) (typically the locomotive of the train (TR)), which is controlled by or in communication with a train management computer (TMC).
Switches that are not equipped with such a wayside interface unit, or a faulty wayside interface unit, will not report any status. If the status of a switch is unknown, the train management computer facilitates crew input related to the actual position of the switch, i.e., normal or reverse. This information is critical for proper navigation, but does represent a potential hazard for the train if the actual alignment or position of the switch is incorrectly entered by the crew. Specifically, the train may enter a section of track where it does not have authority, which leads to other potential hazards and safety issues.
There are existing low-cost, low-power devices that connect to a circuit controller and indicate the orientation of the switch. For example, one such available device is the RailFly™ device and system of Convergent Communications, Inc., with reference to U.S. Application Publication No. 2011/0118913. As illustrated in FIG. 2, a known switch monitoring arrangement that uses such a device is illustrated. In particular, the above-discussed circuit controller (CC) is provided and is in electrical communication with the switch (S). Further, this circuit controller (CC) is powered by a power source (PS). A switch monitor device (SMD) or sensor is in electrical communication with the circuit controller (CC), such that the switch monitor device (SMD) receives power through the circuit controller (CC) when the switch (S) is in the “Normal” state, and is unpowered when the switch (S) is in the “Reverse” state. While powered, the switch monitor device (SMD) transmits (through the data radio (DR)) a static value associated with or indicating that the switch (S) is aligned normal, and the configuration of the switch monitor device (SMD) does not facilitate any other message, i.e., it is in either an “on” or “off” (or malfunctioning) state. Such an arrangement is effective for use in connection with a mainline switch, since the PTC system communicating with the switch will either receive a “Normal” indication or no indication. In the case where no indication is received, the PTC system (including the communication device (CD) and train management computer (TMC) of the train (TR)) acts to enforce a stop prior to the unknown switch; and, thereafter, requires that the crew confirm the actual switch alignment. Further, such an arrangement may also be effective in connection with mainline switches where the sidings are non-PTC (i.e., non-signaled) territory, such that there would be no need to protect entry into the siding beyond confirmation by the crew that the train was leaving the PTC track.
Accordingly, the use of such devices and arrangements reduces the cost of installing and using a wayside interface unit, which is used to meet the vital monitoring and reporting requirements. In particular, the safety requirements are met by using such a device since no switch monitoring choice has to be made by the device, or validated through vital processing. Instead, and as discussed, the device can only report a single switch position, i.e., “Normal”, and only does so when powered. Accordingly, there remains a hazard associated with incorrect switch position entry by the crew, and, additionally, an operational disruption occurs since the crew must enter the actual switch alignment when it is not received from the device.
While the above-discussed device and arrangement facilitate the effective management of trains through switches in dark territory, there is room in the field of train management for switch alignment detection and enforcement within the track network.